Unsaturated Carboxylic Acids Research Articles

Differential anti-inflammatory biomarkers of the desert truffles Terfezia claveryi and Tirmania nivea revealed via UPLC-QqQ-MS-based metabolomics combined to chemometrics

Chemical profiling of white (Tirmania nivea) and black (Terfezia claveryi) desert truffles using UPLC-MS/MS analysis followed by their discrimination based on their anti-inflammatory biomarkers identified using chemometrics and network pharmacology-based analysis was attempted. 25 compounds were identified using UPLC/MS/MS analysis in the extracts of T. claveryi and T. nivea belonging to saturated and unsaturated fatty acids, phenolic acids, alkanes and carboxylic acids. Identified compounds were forwarded to network-pharmacology-based analysis which revealed that resveratrol, oleic acid, margaric acid, naringenin, behenic acid and lauric acid were the top hit compounds related to anti-inflammatory targets. In-vitro anti-inflammatory testing assessed on LPS-stimulated WBCs revealed that T. claveryi and T. nivea extracts reduced TNF-α to the levels of 32 pg/ml and 55 pg/ml, IL-1β level to 55 and 85 pg/ml, and IFN-γ level to 130 nmol/ml and 175 nmol/ml, respectively. Further, the constructed orthogonal projection to latent structures discriminant analysis (OPLS-DA) model coefficients indicated that T. claveryi exhibited its in-vitro anti-inflammatory activity through down regulation of TNF-α pro-inflammatory markers with margaric acid, oleic acid, naringenin and resveratrol being its biomarkers while T. nivea affected mainly IL-1β and IFN-γ pro-inflammatory markers levels with behenic acid, lauric acid, caffeic acid and docosatetraenoic acid being its chemical markers.

Cinnamic Acid Reduces Inflammation and Apoptosis in Necrotizing Enterocolitis

Necrotizing enterocolitis is characterized by an inflammatory condition in the intestine that could result in intestinal necrosis and cell death. Cinnamic acid, an unsaturated carboxylic acid, possesses anti-inflammatory capacity. However, the regulatory role of cinnamic acid on necrotizing enterocolitis has not been investigated yet. To this end, human fetal colon cells were incubated with increasing concentrations of lipopolysaccharides to establish a necrotizing enterocolitis cell model. Data from 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis showed that lipopolysaccharides, in a dosage-dependent manner, reduced cell viability of fetal human colon cells. Also, cinnamic acid prevented the cytotoxic effect of lipopolysaccharides on fetal human colon cells and increased the cell viability. Furthermore, cinnamic acid attenuated lipopolysaccharides-induced decrease in interleukin-10 and increase in interleukin-6 and tumor necrosis factor-α caused by lipopolysaccharides. The lipopolysaccharides-induced increase in cell apoptosis in fetal human colon cells was accompanied with upregulated B-cell lymphoma 2 protein-associated X protein and downregulated B-cell lymphoma 2 protein. These changes were reversed by cinnamic acid treatment. Lastly, expression of protein for suppressor of cytokine signaling 3 was reduced, while phosphorylation of Janus kinase 2 and signal transducers and activators of transcription 3 were enhanced in lipopolysaccharides-induced fetal human colon cells. Once again, cinnamic acid reversed the expression of suppressor of cytokine signaling 3, phospho- Janus kinase 2, and phospho-signal transducers and activators of transcription 3 in lipopolysaccharides-induced fetal human colon cells. In conclusion, cinnamic acid exerted antiapoptotic and anti-inflammatory effects and protected enterocytes against necrotizing enterocolitis through regulation of signal transducers and activators of transcription-mediated Janus kinase 2/signal transducers and activators of transcription 3 pathway.

Iron-Catalyzed Radical Annulation of Unsaturated Carboxylic Acids with Disulfides for the Synthesis of γ-Lactones.

An efficient aerobic iron-catalyzed annulation of unsaturated carboxylic acids with disulfides has been developed. This procedure proceeds using FeCl3 as the catalyst and KI as an iodine source under an air atmosphere, which provides practical access to a wide range of substituted γ-lactone derivatives. The disclosed method is quite simple, highly atom-economic, environmentally friendly, and tolerates a broad substrate scope.

Uptake, Tissue Distribution, and Elimination of 8:2 Polyfluoroalkyl Phosphate Diesters in Mytilus galloprovincialis.

Although the distribution of 8:2 polyfluoroalkyl phosphate diester (8:2 diPAP) in aquatic environments has been reported, details on its uptake, tissue specificity, and elimination in bivalve mollusks remain to be clarified. The present study is the first report on the accumulation and elimination of 8:2 diPAP in mussels (Mytilus galloprovincialis). The tissue-specific accumulation and depuration of 8:2 diPAP and its metabolites were investigated via semistatic seawater exposure (8:2 diPAP at a nominal concentration of 10 μg/L), through water-borne exposure with static daily renewal over a 72-h exposure period and a 360-h depuration period. The digestive gland was found to be the target organ where accumulation and biotransformation primarily occur. The bioaccumulation factor values (mL/g dry wt) in different organs were in the following order: digestive gland (1249) > adductor muscle (315) > gills (289) > gonad (82.9) > mantle (33.0). Moreover, the distribution of 8:2 diPAP among tissues may be related to the total protein content. The 8:2 diPAP tended to be excreted in feces. The compounds 8:2 fluorotelomer carboxylic acid, 8:2 fluorotelomer unsaturated carboxylic acid, 7:3 fluorotelomer carboxylic acid, perfluorooctanoic acid, and perfluoroheptanoic acid were detected and quantified as phase I metabolites, and the concentration of all phase I metabolites relative to the 8:2 diPAP concentration (72 h) was 0.304 mol%. A phase II metabolite, 8:2 fluorotelomer alcohol conjugated with sulfate, was detected but not quantitated in the digestive gland. A biotransformation pathway of 8:2 diPAP in M. galloprovincialis was proposed on the basis of the results obtained in the present study and previous studies. These findings improve our understanding of the accumulation of perfluorocarboxylic acids in bivalve mollusks.Environ Toxicol Chem 2021;40:1992-2004. © 2021 SETAC.

Novel Aza‐Michael Addition‐Asymmetric Protonation to α,β‐Unsaturated Carboxylic Acids with Chiral Thiourea‐Boronic Acid Hybrid Catalysts

AbstractNovel aza‐michael addition‐asymmetric protonation to unsaturated carboxylic acids with chiral thiourea‐boronic acid hybrid catalysts. #asymmetric protonationIn this study, an efficient method has been developed for controlling carbonyl α‐chirality with functionalizing β‐position by the conjugate addition‐asymmetric protonation (CAAP) of α,β‐unsaturated carboxylic acids using chiral thiourea‐amino boronic acid hybrid catalysts. In addition, the method is applied to the asymmetric synthesis of biologically active compounds.

Asymmetric hetero-Michael addition to α,β-unsaturated carboxylic acids using thiourea–boronic acid hybrid catalysts

The first catalytic asymmetric Michael addition of heteroatomic nucleophiles to α,β-unsaturated carboxylic acids is summarized. Direct Michael addition is one of the most straightforward and atom-economical methods for constructing pharmaceutically beneficial building blocks and intermediates, although unsaturated carboxylic acids are known to be inactive Michael acceptors. We designed hybrid catalysts comprising arylboronic acid, thiourea, and tertiary amine to activate the unsaturated carboxylic acids. This review describes the aza- and thia-Michael additions using chiral multifunctional hybrid catalysts, their synthetic applications to biologically active compounds, and the mechanistic consideration of multicomponent borate complexes.

Study of the Impact of Nonionic Additives on the Composition and Structure of Petroleum Dispersed Systems by IR Spectroscopy

The article describes a technique for obtaining a quantitative assessment of the composition and structure of the petroleum dispersed system (PDS) and its individual structural formations based on the data of the component composition and infrared spectroscopy. In the PDS of heavy petroleum feedstock modified with a mixture of unsaturated carboxylic acids and four atomic alcohols, the components of the core and the inner solvation shell are different in structure. The degree of affinity of the components of the inner and outer solvation shells of the complex structural unit (CSU), as well as that of the outer solvation shell and the hydrocarbon components of the dispersion medium, increases. Nonionic additives are involved, to a greater degree, in structuring the solvation shell of the CSU and also increase the degree of its affinity with the hydrocarbon components, which leads to an increase in the dispersion of the system and a decrease in its mobility.

Study of biotransformation of cholesterol 3β-methyl ether by mycobacteria Mycobacterium sp.

The influence of exogenous factors on the selectivity of biotransformation of cholesterol 3β-methyl ether by Mycobacterium sp. was studied. The main product of the microbiological transformation was Δ5-dehydroepiandrosterone 3β-methyl ether. The presence of methyl-β-cyclodextrin in the bacterial growth medium led to a change in the ratio of the reaction products and an increase in the yield of Δ4-androstene-3,17-dione. Aliphatic saturated and unsaturated carboxylic acids were also formed in the course of biotransformation.

Synthesis of the Proposed Isomers of the Deep-Sea Mussel Metabolites Bathymodiolamides A and B.

The first total synthesis of bathymodiolamides A and B, ceramide-like metabolites of the deep-sea hydrothermal vent mussel Bathymodiolus thermophilus, was accomplished in eight linear steps starting from Garner's aldehyde and three carboxylic acids. A sequence of vinylation of Garner's aldehyde, N-acylation with lauric acid, dihydroxylation of the terminal alkene, and stepwise Steglich-Hassner esterifications of the resulting vicinal diol with the respective saturated and unsaturated carboxylic acids, which had to be prepared separately, afforded the target products in 38 and 39% yield. We found distinct discrepancies between their NMR data and antiproliferative activities and those reported for the natural isolates.

Di-tert-butyl Peroxide (DTBP)-Mediated Oxysilylation of Unsaturated Carboxylic Acids for the Synthesis of Silyl Lactones.

Herein, we describe the first oxysilylation of unsaturated carboxylic acids mediated by di-tert-butyl peroxide (DTBP), which enables the rapid and efficient preparation of silyl lactone compounds. This process tolerates functional groups, such as methyl, methoxy, halogen (fluoride and chloride), and cyano moieties. Furthermore, the strategy allows the application of a wide range of primary, secondary, and tertiary hydrosilanes for functionalization.

Antifeedant Activity of Pyrazolin-5-One Derivatives

A series of substituted 4-{1-aza-2-[(aryl) amino)]}-3-methyl-2-pyrazolin-5-ones has been synthesized and evaluated for their biological activity. The title compounds (4a-l) were prepared by the diazotization of substituted anilines (1a-l) to form substituted phenyl hydrazine derivatives (2a-l) which synthesized substituted 4-{1-aza-2-[(aryl) amino)]}-3-methyl-2-pyrazolin-5-ones (4a-l) by Michael addition reaction, which is a nucleophilic addition of enolate anion to the carbon-carbon double bond of a α, β–unsaturated carboxylic acid derivatives. Twelve different pyrazolinone derivatives (4a to 4l) were synthesized. Structural assignments of these compounds have been made by elemental analysis, FTIR, 1HNMR and Mass spectral data and the purity of the compounds was determined by TLC. The antifeedant activity of the newly isolated heterocyclic compounds was evaluated against agriculture pest Achoea janata. Compound 4d found to be very effective as antifeedant while rest of the compounds showed a moderate to good degree of antifeedant activity.

Synthesis of trifluoromethyl substituted nucleophilic glycine equivalents and the investigation of their potential for the preparation of α-amino acids

Abstract The synthetic preparation of several Ni(II) complexed Schiff Bases of glycine will be introduced, as well as investigations into their reactivity and utility. Key to these investigations is the incorporation of electron-withdrawing trifluoromethyl groups within the framework of the conjugated system that stabilizes the enolate derived from the glycine component. Reactivity was evaluated for each of the complexes under phase transfer catalyzed alkylations with hydroxide bases, as well as the DBU catalyzed Michael Additions of optically active 3′-substituted-2-oxazoladinone amides of unsaturated carboxylic acids. It was found that the trifluoromethyl containing nucleophilic glycine equivalents were more reactive than their non-trifluoromethyl analogues in both reaction types. Therefore, the application of these modified Ni(II) complexes of glycine Schiff Bases are useful for the preparation of α-amino acids through phase transfer catalyzed alkylation as well as the preparation of optically pure β-substituted pyroglutamic acid precursors.

Stereoselective Access to Azetidine-Based α-Amino Acids and Applications to Small Peptide Synthesis.

Non-natural azetidine-based amino acids (Aze) present interesting features in protein engineering. A simple organometallic route toward unsaturated carboxylic acid precursors is presented. Subsequent metal-catalyzed asymmetric reduction allowed for the synthesis of a new library of 2-azetidinylcarboxylic acids, which were finally employed in the formation of small peptide chains.

Cycloaddition reactions of o-quinone methides with polarized olefins

The review summarizes and systematizes the [4+2]-cycloaddition reactions of o-quinone methides with electron-rich and electron-deficient olefins. The electron-rich substrates include vinyl ethers, vinyl sulfides, enamines, enamides, enols, furans, benzofurans and indoles, while the electron-deficient substrates are esters of unsaturated carboxylic acids, vinyl azides and quinones. Reactions with push-pull and captodative olefins are also considered. The mechanisms of some reactions are presented. A separate part of the review addresses reactions of p-quinone methides containing an o-hydroxyphenyl substituent at the exocyclic carbon atom, which can isomerize to o-quinone methides. Much attention is paid to oligomerization of o-quinone methides, which proceeds in the absence of active dienophiles or nucleophiles.The bibliography includes 217 references.

Biotransformation and tissue bioaccumulation of 8:2 fluorotelomer alcohol in broiler by oral exposure

In order to examine whether 8:2 FTOH exposure would lead to a contamination risk of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in broiler derived food, the biotransformation, and tissue distribution and accumulation of 8:2 FTOH following oral exposure in male broilers were investigated. The main metabolites of 8:2 FTOH in plasma and six tissues (muscle, liver, kidney, fat, heart, and lungs) identified by LC-Q-TOF were 2-perfluorooctyl ethanoic acid (8:2 FTCA), 8:2 fluorotelomer unsaturated carboxylic acid (8:2 FTUCA), 3-perfluoroheptyl propanoic acid (7:3 FTCA), perfluoropentanoic acid (PFPeA), perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHxA), perfluorononanoic acid (PFNA), 8:2 FTOH glucuronide conjugate, and 8:2 FTOH sulfate conjugate. The tissue distribution and bioaccumulation of 8:2 FTOH and its unconjugated metabolites were determinated by LC-MS/MS. 8:2 FTOH was quickly depleted in plasma and all six tested tissues, while PFOA, PFNA, and 7:3 FTCA showed strong accumulation in blood and all six examined tissues and were eliminated more slowly than the other metabolites. The tissues with the highest accumulation levels for 8:2 FTOH and its metabolites were heart, kidneys and liver, and the tissue with the lowest accumulation levels was muscle. The elimination half-lifes of PFNA in kidney and 7:3 FTCA in lung were longer compared to those of other metabolites in all six determined tissues. Thus, PFNA and 7:3 FTCA can be selected as potential biomonitoring markers after 8:2 FTOH exposure. This study has improved our understanding of 8:2 FTOH biotransformation and tissue bioaccumulation in broilers, which will help us monitor human exposure risk via food derived from broilers polluted by 8:2 FTOH.

Synthesis of Oxygen-Containing Heterocyclic Compounds by Iron-Catalyzed Alkylative Cyclization of Unsaturated Carboxylic Acids and Alcohols.

Iron-catalyzed alkylative cyclization of alkenes bearing oxygen nucleophiles with secondary and tertiary alkyl bromides through carbon-carbon and carbon-oxygen bond formations has been developed. A broad substrate scope is an attractive feature of this synthetic method, providing a variety of potentially bioactive five- and six-membered oxygen-containing heterocycles. The reaction pathway is proposed to involve a radical addition of the in situ-formed alkyl radical to an alkene followed by carbon-oxygen bond-forming intramolecular cyclization.

Noncovalent Interaction-Assisted Ferrocenyl Phosphine Ligands in Asymmetric Catalysis.

Noncovalent interactions are ubiquitous in nature and are responsible for the precision control in enzyme catalysis via the cooperation of multiple active sites. Inspired by this principle, noncovalent interaction-assisted transition metal catalysis has emerged recently as a powerful tool and has attracted intense interest. However, it is still highly desirable to develop efficient and operationally convenient ligands along this line with new structural motifs. Based on the specific nature of hydrogen bonding and ion pairing interactions, we developed a series of noncovalent interaction-assisted chiral ferrocenyl phosphine ligands, including Zhaophos, Wudaphos, and miscellaneous SPO-Wudaphos. Due to the assistance of noncovalent interactions, this catalytic mode is capable of achieving transition metal catalyzed asymmetric hydrogenation and other transformations with remarkable improvement of reactivity and selectivity. In some specific challenging cases, this probably represents one of the most productive methods. Moreover, these ligands are easily prepared, air stable, and highly tunable, meeting the requirements of industrial application.In this Account, we give a concise review of recent advances in asymmetric catalysis. By means of hydrogen bonding interactions, Rh- and Ir-Zhaophos complexes exhibited excellent activities and enantioselectivities in asymmetric hydrogenation of a wide range of substrates: C═C bonds of substituted conjugate alkenes with neutral hydrogen bond acceptors, including nitro groups, carbonyl groups (ketones, esters, amides, maleinimides, and anhydrides), ethers, and sulfones; C═N bonds of substituted iminium salts with chloride as an anionic hydrogen bond acceptor, including N-H imines and cyclic imines; N-heteroaromatic compounds with HCl as an additive, including unprotected quinolines, isoquinolines, and indoles; carbocation of substituted oxocarbenium ions. By means of ion pairing interactions, Rh-Wudaphos complexes enabled the catalytic asymmetric hydrogenation of α-substituted unsaturated carboxylic acids, carboxy-directed α,α-disubstituted terminal olefins, and sodium α-arylethenylsulfonates. Rh-SPO-Wudaphos utilized both hydrogen bonding and ion pairing interactions in asymmetric hydrogenation of α-substituted unsaturated carboxylic acids and phosphonic acids. In addition, Zhaophos has achieved highly selective intramolecular reductive amination and inter- and intramolecular asymmetric decarboxylative allylation. Investigations into mechanism implied that noncovalent interactions were involved in the catalytic cycle and played a critical role for both high reactivity and selectivity. Notably, a rare ionic hydrogenation pathway has been proposed in some cases. Furthermore, these catalytic systems have been used in the gram-scale synthesis of natural products and pharmaceuticals.

Metal‐Free Aerobic Sulfenyllactonization of Unsaturated Carboxylic Acids with Thiols Using Air as Sole Oxidant

AbstractA metal‐free aerobic sulfenyllactonization of unsaturated carboxylic acids with thiols has been disclosed. This method proceeded with air as the sole oxidant, without any metal catalyst, which provides an efficient access to a wide range of sulfenylated lactones with moderate to good yields. The operational simplicity, high atom efficiency, scalability and the use of bio‐based green solvent under mild conditions are the attractive features of this methodology.

Construction of an engineered biocatalyst system for the production of medium-chain α,ω-dicarboxylic acids from medium-chain ω-hydroxycarboxylic acids.

Medium-chain α,ω-dicarboxylic acids produced from renewable long-chain fatty acids are valuable as precursors in the chemical industry. However, they are difficult to produce biologically at high concentrations. Although improved biocatalyst systems consisting of engineering of Baeyer-Villiger monooxygenases are used in the production of ω-hydroxycarboxylic acids from long-chain fatty acids, the engineering of biocatalysts involved in the production of α,ω-dicarboxylic acids from ω-hydroxycarboxylic acids has been rarely attempted. Here, we used highly active bacterial enzymes, Micrococcus luteus alcohol dehydrogenase and Archangium violaceum aldehyde dehydrogenase, for the efficient production of α,ω-dicarboxylic acids from ω-hydroxycarboxylic acids and constructed a biocatalyst with cofactor regeneration system by introducing NAD(P)H flavin oxidoreductase as the NAD(P)H oxidase. The inhibition of the biocatalyst by hydrophobic substrates was attenuated by engineering a biocatalyst system with an adsorbent resin, which allowed us to obtain 196 mM decanedioic, 145 mM undecanedioic, and 114 mM dodecanedioic acid from 200 mM of C10, C11, and C12 hydroxyl saturated carboxylic acids, respectively, and 141 mM undecanedioic acid from 150 mM C11 unsaturated carboxylic acids, with molar conversions of 98%, 97%, 95%, and 94%, respectively. The concentration of undecanedioic acid obtained was approximately 40-fold higher than that in the previously highest results. Our results from this study can be applied for the industrial production of medium-chain α,ω-dicarboxylic acids from renewable long-chain fatty acids.

Radical Strategy for the Transition-Metal-Catalyzed Synthesis of γ-Lactones: A Review

The γ-lactone skeleton is very important component of various natural products, biological molecules, food additives, and perfumes. As a result, much effort has been made towards such compounds. In this review, we summarize recent progress in transition-metal-catalyzed annulation reactions for the formation of γ-lactone derivatives through a radical pathway. Various reagents, such as anhydrides, Togni’s reagent, TMSN3, arenesulfonyl chlorides, arenediazonium salts, dibenzoyl peroxides, O-benzoylhydroxylamine, NFSI, and α-halocarboxylic compounds, used in radical cyclization reactions are described, and the mechanisms of these radical annulation reactions are also discussed.1 Introduction2 Annulations of Alkenes with Anhydrides3 Annulations of Unsaturated Carboxylic Acids with Nucleophiles4 Annulations of Alkenes with α-Halocarboxylic Compounds5 Conclusions and Outlook